The subject matter of the present invention relates generally to stands for supporting electronic instruments with light image displays and in particular to a cathode ray tube display device stand which enables tilting of the stand in a vertical direction, swiveling of the stand in a horizontal plane and adjustment of the height of the stand above a support surface and gliding movement over such support surface. The stand of the present invention is especially useful for supporting a computer display terminal to enable optimum ergonomic positioning of the terminal to a comfortable position for most users to prevent physical ailment problems such as headache, eye strain, sore neck, backache, vision glare and to avoid overextended distances for performing work tasks associated with the computer terminal.
Previously, it has been proposed by Nixdorf Computer AG of Paderborn, West Germany to provide a computer terminal stand with an adjustable height having a terminal support plate attached by a single post to a swivel base, such support plate tilting about a tilt axis at the top of the support post. However, unlike the present invention, the single support post does not telescope but instead pivots at the bottom end thereof about a pivot axis connected to the swivel base for adjusting the height of the computer terminal. This has the disadvantage that the height adjustment also causes movement of the computer terminal toward and away from the user with changes in elevation. In addition, the entire weight of the computer terminal is supported on the single support post so that it is difficult to adjust the height and is awkward to tilt the terminal on the support plate attached to the top of the support post. Unlike the present invention, the Nixdorf stand does not employ a pair of telescopic arms on opposite sides on the computer terminal and does not use a gas spring to counterbalance the weight of the terminal. Furthermore, there is no releasable brake which enables gliding movement of the base over the support surface when the brake is released and swivel movement of the base when the brake is engaged.
It has also been proposed by Florida Computer Graphics of Lake Mary, Fla. to provide a computer terminal stand for their Beacon model having a height adjustmet as well as swivel and tilt adjustments. However, unlike the present invention, it does not employ telescoping support posts or use a gas cylinder counterbalance means. In additionm there is no releasable brake to enable gliding movement of the swivel base, in the manner of the present invention.
Tandberg Data, A/S of Oslo, Norway provides a computer terminal stand for their Model TDV2200 terminal with a single telescoping support post to adjust elevation of the stand apparently by a gear means, but without using a gas spring counterbalance in the manner of the present invention. As a result, an elevation adjustment of only approximately 3.5 inches is achieved with the Tandberg stand as opposed to a height adjustment of 6.0 inches with the stand of the present invention. In addition, the tilt angle is limited to a range of approximately 25.degree., whereas a greater tilt angle range of 35.degree. is achieved by the present invention. The swivel base of the Tandberg stand swivels through a maximum angle of 60.degree., while the present invention can swivel through a greater angle range of 360.degree.. The stand of the invention is designed with the range of adjustment to meet the needs of the 5% to 95% of the user population. In addition, there is no releasable brake on the base of the Tandberg stand to enable gliding movement across the support surface when the brake is released in the manner of the present invention.